KR20190082221A - Quantum dot light emitting element - Google Patents

Abstract

The present invention relates to a process for preparing a compound of Group II-VI compound, II-V compound, III-VI compound, III-V compound, IV-VI compound, I-III-VI compound, II-IV-VI compound Emitting layer of at least one semiconductor nanoparticle made of a semiconductor material selected from the group consisting of Group II-IV-V compounds, or any combination thereof, and ii) the diode comprises at least one triaryl There is provided a quantum dot light emitting diode comprising a polymer for hole injection or hole transporting layer containing an aminium radical cation.

Description

Quantum dot light emitting element

This disclosure relates to electronic devices, particularly quantum dot light emitting diodes.

The quantum dot light emitting diode (QLED) is an electroluminescent device that uses various organic and inorganic layers, sometimes combined with the emissive layer of semiconductor nanoparticles called a quantum dot (QD). The QLED quantum dot layer can emit light when electricity is applied to the device. Thus, QLEDs can be used as light sources in display and general illumination applications. One limitation of QLEDs is that there is no suitable hole-transport layer (HTL) to efficiently inject charge into the quantum dot layer. If the charge injection into the quantum dots is insufficient, a QLED device having a high operating voltage and a low light generating efficiency is obtained.

Therefore, there is a continuing need for new hole-transporting materials that enable improved QLED devices with high brightness and color purity, minimum power consumption, and high reliability.

 The present invention relates to a process for preparing a compound of Group II-VI compound, II-V compound, III-VI compound, III-V compound, IV-VI compound, I-III-VI compound, II-IV-VI compound , At least one semiconductor nanoparticle made of a semiconductor material selected from the group consisting of Group II-IV-V compounds, or any combination thereof, and ii) at least one triarylammonium radical having structure (S1) There is provided a quantum dot light emitting diode comprising a polymer for positive hole injection or hole transporting layer,

Each ^{R 11, R 12, R 13} , R 14, R 15, R 21, R 22, R 23, R 24, R 25, R 31, R 32, R 33, R 34, and R ³⁵ is hydrogen, Is selected from the group consisting of hydrogen, deuterium, halogen, an amine group, a hydroxyl group, a sulfonate group, a nitro group, and an organic group; ^{R 11, R 12, R 13} , R 14, R 15, R 21, R 22, R 23, R 24, R 25, R 31, R 32, R 33, R 34, and R ³⁵ 2 out of the above Optionally linked together to form a ring structure; ^{R 11, R 12, R 13} , R 14, R 15, R 21, R 22, R 23, R 24, R 25, R 31, R 32, R 33, R 34, and R ³⁵ at least one of the said Covalently bonded to the polymer; A ^- is an anion.

 The quantum dot light emitting device of the present invention may comprise an anode layer, optionally one or more hole injecting layers, at least one hole transporting layer, optionally at least one electron blocking layer, a light emitting layer, optionally at least one hole blocking layer, optionally at least one electron transporting layer, One or more electron injection layers, and a cathode.

 The light emitting layer includes at least one semiconductor nanoparticle.

 The layer functioning either as the hole injection layer or the hole transporting layer or as the hole injection layer and the hole transporting layer or as either or both of the hole injection layer and / or the hole transporting layer includes the polymer described below.

 The light-

The light emitting layer of the QLED includes semiconductor nanoparticles. In some embodiments, the semiconductor nanoparticles may comprise elemental, binary, tertiary or epitaxial semiconductors. The semiconductors may include, if desired, five or more elements. In some embodiments, the composition of the semiconductor nanoparticles is selected from the group consisting of Group IV compounds, Group II-VI compounds, Group II-V compounds, Group III-VI compounds, Group III-V compounds, Group IV-VI compounds, Group II-IV-VI compounds, Group II-IV-V compounds, or any combination thereof. In some embodiments, the composition of the semiconductor nanoparticles may include metal oxides such as ZnO and TiO ₂ . In some embodiments, the composition of the semiconductor nanoparticles may include a perovskite material such as methylammonium lead trihalide. In some embodiments, the semiconductor nanoparticles may include CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, InP, CuInSe _2, or any combination thereof. In some embodiments, the semiconductor nanoparticles may comprise a heterojunction. In some embodiments, the semiconductor nanoparticles may comprise a graded composition, whereby such a composition transitions at a constant distance from the first composition to the second composition.

 The semiconductor nanoparticles may not be doped; Or a rare earth element such as Eu, Er, Tb, Tm or Dy; And / or transition metal elements such as Mn, Cu, and Ag; Or any combination thereof.

 In some embodiments, the semiconductor nanoparticles have a length of at least one dimension of 100 nanometers or less, a length of 50 nanometers or less, or even 20 nanometers or less. In some embodiments, the size of the semiconductor nanoparticles in the light emitting layer may have a distribution. In some embodiments, the size distribution of the semiconductor nanoparticles may be a single-rod or multi-rod type. In some embodiments, the semiconductor nanoparticles have an isotropic or anisotropic dimension.

In some embodiments, the semiconductor nanoparticles may have a core-shell structure in which the interior of the semiconductor nanoparticles is coated with additional material (known as "shell"). The shell may be composed of a semiconductor or an insulator. In some embodiments, the composition of the shell is selected from the group consisting of Group IV compounds, Group II-VI compounds, Group II-V compounds, Group III-VI compounds, Group III-V compounds, Group IV-VI compounds, Group I-III-VI compounds And Group II-IV-VI compounds, Group II-IV-V compounds, or any combination thereof. In another embodiment, the composition of the shell may include a metal oxide such as ZnO and TiO _2. In other embodiments, the composition of the shell may include a perovskite material such as methylammonium lead trihalide. In some embodiments, the composition of the shell may include CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, InP, CuInSe _2, or any combination thereof. In some embodiments, the shell may comprise a single layer or multiple layers. In some embodiments, the shell may comprise a graded composition such that such a composition transitions at a constant distance from the first composition to the second composition. In some embodiments, the composition can be graded continuously from the interior of the semiconductor nanoparticle to the shell. In some embodiments, the shell may have a thickness of 100 nanometers or less, 50 nanometers or even 5 nanometers or less.

 The surface of the semiconductor nanoparticles is filled with molecular and / or endcapping inorganic molecules, sometimes referred to as ligands, such as alkylphosphines, alkylphosphine oxides, amines, carboxylic acids and the like, which enable dispersion in various solvents , And the aggregation and fusion of nanoparticles.

 Ligand molecules can be covalently or noncovalently bound to quantum dots through functional groups that can interact either covalently or non-covalently with the outermost layers of the quantum dots. In some embodiments, the functional group may be selected from the list including, but not limited to, phosphines, phosphine oxides, carboxylic acids, amines, and alcohols. In some embodiments, a second functional group is present on the ligand such that the first functional group interacts with the quantum dot surface and the second functional group interacts with the ligand on the adjacent quantum dot.

 In some embodiments, the functional group on the ligand molecule has an organic substituent, such as but not limited to a saturated alkyl group, an unsaturated alkyl group, an aromatic group, a linear alkyl group, a non-linear alkyl group, a branched alkyl group, an ether group, or an amine group. In some embodiments, the ligand layer may comprise a mixture of one or more molecular types. The ligand layer may have any desired thickness in accordance with embodiments of the present invention. In some embodiments, the ligand layer has a thickness of 15 nanometers or less, or 10 nanometers or less, or even 3 nanometers or less. In some embodiments, the ligand molecule forms a complete monolayer or sub-monolayer on the surface of the quantum dot.

 In some embodiments, the semiconductor nanoparticles may be one-dimensional. The one-dimensional nanoparticles have a characteristic thickness dimension (for example, a diameter or a diagonal in the case of a circular cross section or a diagonal in the case of a rectangular cross section) of 1 nm to 1000 nm (nanometer), preferably 2 nm to 50 nm, Has a cross-sectional area of 5 nm to 20 nm (e.g., about 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, . The nanorods are rigid rods having a circular cross-sectional area with characteristic dimensions within the ranges described above. The nanowire or nanowhisker is a curved surface, each having a different silicate or insect shape. The nanoribbons have a cross-sectional area bounded by four or five linear sides. Examples of such a cross-sectional area include a square, a rectangle, a parallelepiped, and an oval-shaped body. Nanotubes are similar to tubes, having a substantially concentric hole across the entire length of the nanorod. The aspect ratio of such one-dimensional nanoparticles is 2 or more, preferably 5 or more, and more preferably 10 or more.

 The one-dimensional nanoparticles have a length of 10 to 100 nanometers, preferably 12 to 50 nanometers, and more preferably 14 to 30 nanometers. The one-dimensional nanoparticles may have a diameter of 2 to 10 nanometers, preferably 3 to 7 nanometers. The one-dimensional nanoparticles have an aspect ratio of about 2 or more, preferably about 4 or more.

 In one exemplary embodiment, the semiconductor nanoparticles comprise a one-dimensional nanoparticle in which a single end cap or a plurality of end caps in contact with the one-dimensional nanoparticles are disposed at either or each end. In one embodiment, the end caps also contact each other. The end cap serves to passivate one-dimensional nanoparticles. The nanoparticles may be symmetrical or asymmetric about at least one axis. The nanoparticles can be asymmetric in composition, end cap composition, geometric and electronic structure, or both in composition and structure.

 In one embodiment, the nanoparticles include one-dimensional nanoparticles that include end caps at each opposite end along their longitudinal axis. Each end cap has a different composition, providing multiple heterojunctions to the nanoparticles. In another embodiment, the nanoparticles include one-dimensional nanoparticles comprising end caps at each opposite end along their longitudinal axis, and further comprise a node disposed on the radial surface or end cap of the one-dimensional nanoparticle. The radial surface is also referred to as the lateral surface of the rod. As long as one of the end caps has a different composition than at least one of the other end caps or nodes, the end caps may have similar or different compositions and / or the nodes may have similar or different compositions to each other.

 In one embodiment, the plurality of end caps include a first end cap and a second end cap that partially or completely surrounds the first end cap. The end cap is a three-dimensional nanoparticle, at least one of which is in direct contact with the one-dimensional nanoparticle. Each end cap may or may not contact the one-dimensional nanoparticle. The first end cap and the second end cap may have different compositions. Also, a node is a three-dimensional nanoparticle that may be smaller or larger than an endcap.

 The term "heterojunction" refers to a structure in which one semiconductor material is in direct contact with another semiconductor material.

 The one-dimensional nanoparticles, the first end cap, and the second end cap each comprise a semiconductor. The interface between the nanorod and the first end cap provides a first heterojunction and the interface between the first end cap and the second end cap provides a second heterojunction. In this manner, the nanoparticles may comprise a plurality of heterojunctions.

 In one embodiment, the heterojunction where the one-dimensional nanoparticles are in contact with the first end cap has a type I or quasi-type II band alignment. In other embodiments, the point at which the second end cap contacts the first end cap has a Type I or quasi-type II band alignment.

The first end cap and second end cap and with each other chemically different from, Si, Ge, Pb, SiGe , ZnO, TiO 2, ZnS, ZnSe, ZnTe, CdO, CdS, CdSe, CdTe, MgO, MgS, MgSe, MgTe HgO, HgS, HgTe, AlN, AlP, AlSb, GaN, GaP, GaAs, GaSb, InN, InP, InAs, InSb, TlN, TIP, TlAs, TlSb, TlSb, PbS, PbSe, PbTe, Or a combination comprising at least one of the foregoing semiconductors. In an exemplary embodiment, the first end cap is CdTe or CdSe and the second end cap is ZnSe.

 By varying the composition and size (diameter or length) of the one-dimensional nanoparticles, the first end cap, and / or the second end cap, the energy band gap and band offset can be varied. Changing the energy band gap can change the wavelength, efficiency, and intensity of light generation in nanoparticles. In one embodiment, the conduction band offset between the first end cap and the one-dimensional nanoparticle is much higher than the conduction band offset between the first end cap and the second end cap, and the conduction band offset between the first end cap and the one- The offset is much lower than the valence band offset between the first end cap and the second end cap. In another embodiment, the conduction band offset between the first end cap and the one-dimensional nanoparticle is much lower than the conduction band offset between the first end cap and the second end cap, and the conduction band offset between the first end cap and the one- The offset is much lower than the valence band offset between the first end cap and the second end cap. In another embodiment, one of the two heterojunctions formed by the first end cap has a smaller conduction band offset and a larger valence band offset than the other, and the other has a larger conduction band offset and a smaller Lt; / RTI >

 In one embodiment, the nanoparticles include two types of heterojunctions, the staggered band offsets of type II enable efficient injection of electrons and holes, and the type I offsets define a recombination center for highly efficient luminescence.

 In one embodiment, the nanoparticles can be used to form a layer or film. In one embodiment, the layer can be disordered. In other embodiments, the layer may have liquid crystallinity. In other embodiments, the layers can be ordered in a single dimension. In other embodiments, the layer may be ordered in two or three dimensions. In other embodiments, the nanoparticles can be self-assembled into a lattice within the film.

 In some embodiments, the anisotropic nanoparticles can be aligned in layers within the device. In one embodiment, the anisotropic nanoparticles can be aligned such that the one-dimensional axis of the particles is perpendicular to the surface of the layer. In other embodiments, the anisotropic nanoparticles can be aligned in the plane of the layer. In other embodiments, the anisotropic particles can be aligned such that the one-dimensional axes of the plurality of anisotropic particles are aligned in the same direction.

Polymer for hole injection / transport layer

The polymers of the present invention comprise a wide variety of polymer compositions. Some preferred types of polymers are vinyl polymers, polyurethanes, polyamides, polycarbonates, polyepoxies, and conjugated polymers. That is, the polymer is preferably a carbon-carbon double bond, or a urethane bond, or a urea bond, or an ester bond, or an amide bond, or an OCH ₂ CH (OH) CH ₂ - bond; Or a reaction product of an sp ² hybridized carbon-carbon single bond; More preferably a reaction product of a carbon-carbon double bond or sp ² hybridized carbon-carbon single bond; More preferably a reaction product of a carbon-carbon double bond.

 The polymer contains structure (S1): < RTI ID = 0.0 >

Structure (S1) is referred to herein as a triarylammonium radical cation.

^{R 11, R 12, R 13} , R 14, R 15, R 21, R 22, R 23, R 24, R 25, R 31, R 32, R 33, R 34, and R ³⁵ groups of the terms " S1R " Each of the S1R groups is independently selected from hydrogen, deuterium, halogen, an amine group, a hydroxyl group, a sulfonate group, a nitro group, and an organic group. One or more S1R groups are covalently bonded to the polymer.

In some embodiments (herein, "ring embodiments"), two or more S1R groups are covalently bonded to each other to form a ring structure. Among the ring embodiments, it is preferred that (i) the S1R group pairs bonded to each other are adjacent to each other on a single aromatic ring, or (ii) the S1R group pair is selected from R ³¹ to R ²⁵ ; R ¹⁵ to R ³⁵ ; And R ¹¹ to R ^21. In case (ii), the two bonded < RTI ID = 0.0 > S1R < / RTI > groups may be bonded in such a way that the single valence of the combined S1R group is bonded to the two aromatic rings shown in structure Sl. Another possibility in case (ii) is that there is no atom in the combined S1R group; Such an S1R group consists of a bond connecting a carbon atom on one of the aromatic rings shown in structure (S1) to a carbon atom on one of the other aromatic rings shown in structure (S1).

Each Aminium radical cation S1 group is associated with the anion A ^- . The anion A ^- can be of any composition. Negative ions A ^- can be placed in various positions. For example, A ^- can be a covalently bonded group to the polymer containing structure (S1), or A ^- can be an individual atom or molecule. Preferably, A < ^- > is not covalently bonded to the polymer containing structure (S1). A ^- may be an atomic anion or a molecular anion. Molecular anions may be dimers or oligomers or polymers, or molecules that are not dimers or oligomers or polymers. Preferably, A < ^- > is a non-polymeric molecular anion.

Preferred anions A ^- are BF ₄ ^- , PF ₆ ^- , SbF ₆ ^- , AsF ₆ ^- , ClO ₄ ^- , anions of structure SA, anions of structure MA, and mixtures thereof. Rescue SA

(SA)이고,

(SA)

Q is B, Al, or Ga, preferably B, and each of y1, y2, y3, and y4 is independently 0-5, which is present in each of the four aromatic rings shown in structure (SA) Means zero to five R groups (i.e., R ⁶¹ or R ⁶² or R ⁶³ or R ⁶⁴ ). Any pair of R groups in structure (SA) can be the same or different from each other. Each R group in structure (SA) is independently selected from hydrogen, deuterium, halogen, alkyl, or halogen-substituted alkyl. Any two R groups in structure (SA) may be joined together to form a ring structure. Of the anions having a structure SA, anions having at least one R group selected from deuterium, fluorine and trifluoromethyl are preferred.

 Structure MA

(MA)이고,

(MA)

M is B, Al, or Ga, preferably Al; Each of R ⁶⁵ , R ⁶⁶ , R ⁶⁷ , and R ⁶⁸ is independently alkyl, aryl, fluoroaryl, or fluoroalkyl. Preferably, the structure MA has 50 or fewer non-hydrogen atoms. Preferred anions are BF ₄ ^- and anions of structure (SA); And more preferably an anion of structure (SA).

In some suitable embodiments, A < ^- > has a structure (SA) in which one R ⁶¹ group or one R ⁶² group or one R ⁶³ group or R ⁶⁴ group, or combination thereof, has structure (SA2)

(SA2)

(SA2)

Each of R ⁸¹ , R ⁸² , and R ⁸³ is hydrogen or a hydrocarbon group having 1 to 20 carbon atoms; X ¹ is an alkylene group having 1 to 20 carbon atoms; Y ¹ is an alkylene group having 6 to 20 carbon atoms; s1 is 0 or 1; t1 is 0 or 1; And (t1 + s1) is 1 or 2. In structure SA2, the Y ¹ group at the far right is bonded to the carbon atom of the aromatic ring shown in structure SA, which is eventually bonded to Q. When structure (SA2) is present, preferred Q is boron.

 Preferably, the polymer is a vinyl polymer. When the polymer is a vinyl polymer, at least one of the SlR groups contains at least one moiety of a carbon-carbon double bond and a reaction of another carbon-carbon double bond in a vinyl polymerization reaction. Also contemplated are embodiments wherein the polymer is the result of a polymerization reaction involving the reaction of complementary reactors G1 and G2; In this implementation, one of the following situations occurs:

(a) At least one of the S1R groups contains a residue of G1 after reacting with G2 and the other of the S1R groups on the same structure (S1) contains a residue of G2 after reacting with G1, or

(b) Some of the polymerized units contain residues of G1 after two or more of the S1R groups react with G2 respectively and two or more of the S1R groups on the other polymerization units each contain residues of G2 after reacting with G1.

Preferably, two or more of the groups S1R are hydrogen; More preferably 4 or more; More preferably 6 or more; More preferably 8 or more; More preferably 10 or more. Among the S1R groups other than hydrogen, organic groups having 50 or fewer carbon atoms are preferable. Preferably, at least one of R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , and R ¹⁵ is an organic group having at least one aromatic group. Preferably, at least one of R ²¹ , R ²² , R ²³ , R ²⁴ , and R ²⁵ is an organic group having at least one aromatic group. Preferably, at least one of R ³¹ , R ³² , R ³³ , R ³⁴ , and R ³⁵ is an organic group having at least one aromatic group. Preferably, each of R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , and R ¹⁵ is hydrogen or a hydrocarbyl group. Preferably, each of R ²¹ , R ²² , R ²³ , R ²⁴ , and R ²⁵ is hydrogen or a hydrocarbyl group. Preferably, each of R ³¹ , R ³² , R ³³ , R ³⁴ , and R ³⁵ is hydrogen or an organic group containing at least one hetero atom; A preferred heteroatom is nitrogen; Preferably, the heteroatom is part of a heteroaromatic group. Preferably, any < RTI ID = 0.0 > S1R < / RTI > group that is not hydrogen has 50 or fewer atoms different from hydrogen.

 Among the S1R groups other than hydrogen, preferred organic groups are as follows. The attachment point for the structure (S1) is indicated by the jagged line symbol / \ / \. When the monovalent group has two attachment points, it is attached to the adjacent two carbon atoms on one of the aromatic rings in structure (S1).

Each of R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R ⁵⁰ , R ⁵¹ , R ⁵² and R ⁵³ is hydrogen or an organic group. Preferably, R < ⁵ > is an organic group containing hydrogen, an alkyl group, or an aromatic ring. One preferred R < ⁵ > is structure (S14) and the moiety in parentheses is the reactive residue of the carbon-carbon double bond and other carbon-carbon double bonds in the vinyl polymerization reaction. Preferably, n is 1 or 2. Preferred organic groups have 50 or fewer atoms different from hydrogen. The structure (S14) is as follows:

R ⁵⁴ is hydrogen or an alkyl group, preferably hydrogen or a C ₁ to C ₄ alkyl group, preferably hydrogen or methyl, more preferably hydrogen.

Preferably, R ⁴ is an alkyl group (preferably methyl) or a group of structure (S5). In some embodiments, when R ⁴ has structure S5, R ⁵ is structure (S14) and R ¹⁴ is hydrogen. Preferably, R < ⁶ > is hydrogen. Preferably, R < ⁷ > is hydrogen. Preferably, R < ⁸ > is hydrogen. In structures S9 and S10 each of R ⁹ , R ⁵⁰ , R ⁵¹ , R ⁵² and R ⁵³ is preferably hydrogen, an alkyl group, or a group of structure (S5). In structures S9 and S10, n is an integer from 0 to 10; Preferably 0 to 2.

Preferably, R ¹¹ , R ¹² , R ¹⁴ , and R ¹⁵ are both hydrogen. Preferably, R ²¹ , R ²² , R ²⁴ , and R ²⁵ are both hydrogen. Preferably, R ³¹ , R ³⁴ , and R ³⁵ are both hydrogen. (In this specification, "(I)" embodiment in which all of R ¹¹ , R ¹² , R ¹⁴ , R ¹⁵ , R ²¹ , R ²² , R ²⁴ , R ²⁵ , R ³¹ , R ³⁴ and R ³⁵ are hydrogen ) Is more preferable.

Also preferred is an embodiment wherein R ³² and R ³³ together have a structure (S6), preferably R ⁶ is hydrogen (referred to herein as "(II)" embodiment).

Of the embodiments I, II is preferred.

Some preferred implementations herein designated as A Implementation, B Implementation, and C Implementation are as follows.

In an embodiment, R ²³ is structure (S4), preferably R ⁴ has structure (S5), preferably R ⁵ has structure (S14), preferably R ⁵⁴ is hydrogen. In an embodiment, R < ¹³ > is preferably a structure (S5), preferably R < ⁵ > The preferred A implementation is also an I implementation.

In an embodiment B, R < ²³ > is structure S5, preferably R < ⁵ > has structure S14, preferably R < ⁵⁴ > Preferably, R < ¹³ > is structure (S4), preferably R < ⁴ > has structure S5, preferably R < ⁵ > A preferred B implementation is also an I implementation.

In a C embodiment, R ²³ is structure S5, preferably R ⁵ has structure S14, preferably R ⁵⁴ is hydrogen. In a C embodiment, preferably R ¹³ is structure (S5), preferably R ⁵ is hydrogen. A preferred C implementation is also an I implementation.

In some preferred ^{embodiments, R 11, R 12, R} 13, R 14, R 15, R 21, R 22, R 23, R 24, R 25, R 31, R 32, R 33, R 34, and R ³⁵ is selected from substituted or unsubstituted phenyl, substituted or unsubstituted carbazolyl, substituted or unsubstituted indolyl, substituted or unsubstituted fluorenyl, or substituted or unsubstituted biphenyl.

In some preferred embodiments, structure Sl has structure S201:

A, S4, S5, and S12 are as defined above. The exponent m is 0 or 1. The index u is 0 to 3, and 0 to 3 groups in the curly braces having subscript u can be attached to the nitrogen atom. Each S5 group has an R < ⁵ > group attached thereto. In this embodiment, R < ⁵ > is H or styrene or vinyl. When u is 2 or 3, each of the different R ⁸ groups are selected in a different R ⁸ groups independently. The index v is 0 to 3, indicating that from 0 to 3 (S12) groups may be attached to the nitrogen atom. The exponent w is 0 to 3, indicating that 0 to 3 of the groups in the brackets can be attached to the nitrogen atom. Each S4 group has an R ⁴ group attached thereto. In this embodiment, R < ⁴ > is H or styrene or vinyl. When w is 2 or 3, each of the various R < ⁴ > groups is independently selected from other R < ⁴ > groups. (U + v + w) = 3.

 Preferably, the polymer contains, in addition to structure (S1), one or more triarylamine structures having structure (S2):

^{R 11a, R 12a, R 13a} , R 14a, R 15a, R 21a, R 22a, R 23a, R 24a, R 25a, R 31a, R 32a, R 33a, R 34a, and R ^35a suitable and preferred structure for is in structure ^{(S2) R 11, R 12} , R 13, R 14, R 15, R 21, R 22, R 23, R 24, R 25, R 31, R 32, R 33, R 34, and R ³⁵ as described above. ^{R 11a, R 12a, R 13a} , R 14a, R 15a, R 21a, R 22a, R 23a, R 24a, R 25a, R 31a, R 32a, R 33a, R 34a, and R ^35a groups S2R herein . Each S2R group has a label of format R ^ija and is referred to herein as a label of format R ^ij and an S1R unit with i and j of the same value. For example, R ^31a at S2 corresponds to R ³¹ at S1. Each S2R group may or may not be the same as the corresponding S1R group. In some embodiments, one or more S2R group (s) are different from their (corresponding) S1R group (s). Preferably, the polymer contains at least one S2 group in which all S2R groups are the same as the corresponding S1R groups.

 The following is a list of suitable S2 structures ("List A"). It should be noted that each structure in List A contains a nitrogen atom ("triaryl" nitrogen) attached to three aromatic rings. It is contemplated that the triaryl nitrogen atoms in each structure of list A may be oxidized to form aminium radical cations to form the appropriate S1 structure corresponding to the S2 structure shown in List A. Listing A is as follows:

Preferably, in the polymers of the present invention, the molar ratio of S2 group to S1 group is 999: 1 or less; More preferably not more than 500: 1; More preferably not more than 99: 1; More preferably 50: 1 or less; More preferably 20: 1 or less. Preferably, in the polymers of the present invention, the molar ratio of S2 group to S1 group is 0.001: 1 or more; More preferably 2: 1 or more; More preferably 3.5: 1 or more; More preferably 5.5: 1 or more.

The polymers of the present invention preferably have a number average molecular weight of at least 2,500 Da; More preferably 5,000 Da or more, and even more preferably 10,000 Da or more; More preferably 20,000 Da or more; More preferably 40,000 Da or more; More preferably 60,000 Da or more. The polymers of the present invention preferably have a number-average molecular weight of 500,000 Da or less; More preferably 300,000 Da or less; And more preferably 150,000 Da or less.

 In some embodiments, the compositions of the present invention contain both the polymer described above and one or more additional polymers that do not contain structure S1. In some embodiments, the composition contains one or more polymers that do not contain structure S1 and structure S2. If any of these additional polymers are present, the additional polymer is preferably the same type of polymer as the polymer containing structure S1.

 Preferably, the polymer of the invention is at least 99% pure, more preferably at least 99.5% pure, more preferably at least 99.7% pure, as measured by liquid chromatography / mass spectroscopy (LC / MS) on a solid weight basis. Preferably, the formulation of the present invention contains no more than 10 ppm by weight of metal, preferably no more than 5 ppm of metal.

 The polymers of the present invention may be prepared by any method. One method is to polymerize one or more monomers containing structure S1, optionally with one or more other monomers. The preferred method is to first polymerize the one or more monomers containing structure S2 together with one or more other monomers and then apply the resulting polymer to a chemical reaction that converts some or all of structure S2 in the polymer to structure S1. A preferred method of converting some or all of structure S2 to structure S1 is to react the polymer containing structure S2 with one or more oxidizing agents. The reaction with the oxidizing agent is considered to proceed as shown in reaction X1:

는 산화제이고, X^Θ는 음이온이고, S2

는 S1과 같다. 바람직하게는, OA

대 S2의 몰비는 25:1 이하; 보다 바람직하게는 20:1 이하; 보다 바람직하게는 15:1 이하이다. 바람직하게는, OA

대 S2의 몰비는 2:1 이상; 보다 바람직하게는 4:1 이상; 보다 바람직하게는 8:1 이상이다.OA

Is the oxidizing agent and, X ^Θ is an anion, and, S2

Is equal to S1. Preferably, the OA

The molar ratio of S2 to S is 25: 1 or less; More preferably not more than 20: 1; More preferably 15: 1 or less. Preferably, the OA

To S2 is 2: 1 or higher; More preferably 4: 1 or more; More preferably 8: 1 or more.

는 오늄 화합물이다.A preferred oxidizing agent is a compound containing a nitrosonium ion and a compound containing an Ag (I) ion (i.e., a silver ion having a +1 valence). Among the compounds containing Ag (I) ions, Ag (I) tetra (pentafluorophenyl) borate is preferred. Of the compounds containing nitrosonium ions, NOBF ₄ is preferred. In some implementations, OA

Is an onium compound.

 Preferably, the reaction between the polymer and the oxidizing agent is carried out in an organic solvent. When the oxidant is a compound containing Ag (I) ions, the preferred solvent contains at least one aromatic ring; More preferably the aromatic ring has no heteroatom; More preferably the solvent contains one or more heteroatoms which are not located in the aromatic ring; More preferably the solvent is anisole. When the oxidizing agent is a compound containing a nitrosonium ion, the preferred solvent does not contain an aromatic ring; Is preferably a non-aromatic solvent containing at least one heteroatom; Acetonitrile, dichloromethane, and mixtures thereof.

 The polymer may be prepared by any polymerization method.

 In a preferred polymerization method ("vinyl polymerization"), a first monomer containing structure S2 and containing at least one vinyl group is provided. The preferred vinyl group has structure S15

R < ⁵⁴ > is hydrogen or alkyl, preferably hydrogen or methyl, more preferably hydrogen. Preferably, the attachment point shown in structure S15 is attached to the carbon atom of the aromatic ring. The first monomer may optionally be mixed with additional monomers containing vinyl groups, and such additional monomers may or may not contain structure S2 other than the S2 group of the first monomer. Preferably, the first monomer contains exactly one vinyl group per molecule. Optionally, at least one of any additional monomers may be a monomer containing two or more vinyl groups per molecule. In vinyl polymerization, various vinyl groups participate in the polymerization reaction to form a vinyl polymer. Vinyl polymerization can be carried out by free-radical polymerization or by one or more other mechanisms; Preferably by free-radical polymerization. Preferably, after the polymerization, part or all of the S2 group is converted to the S1 group by an oxidation reaction.

 Other polymerization methods different from vinyl polymerization are also contemplated. Among these methods, preferred is a polymerization method ("G1 / G2" method) comprising complementary reactors G1 and G2 that react with each other. In some embodiments, a primary monomer having at least two G1 groups per molecule is provided, the primary monomer is mixed with a secondary monomer having at least two G2 groups per molecule, and one or both of the primary and secondary monomers Has an S2 period. Then, when the G1 and G2 groups react with each other, a polymer is formed. In another embodiment, monomers having groups G1, G2, and S2 are provided. Then, when the G1 and G2 groups react with each other, a polymer is formed. In the G1 / G2 method, additional monomers may optionally be present. Preferably, in the G1 / G2 method, after the polymerization, part or all of the S2 group is converted to the S1 group by an oxidation reaction.

 Preferably, the polymer of the present invention exists as a thin film layer on a substrate. The film is preferably formed on the substrate by a solution-forming process, preferably a spin-coating or an ink-jet process.

 When the solution is prepared to coat the polymer on the substrate, preferably the solvent has a purity of at least 99.8 wt%, preferably at least 99.9 wt%, as determined by gas chromatography-mass spectrometry (GC / MS) . Preferably, the solvent has an RED value of less than 1.2, more preferably less than 1.0 (relative energy difference (to polymer) calculated from Hanse solubility parameter using CHEMCOMP v2.8.50223.1). Preferred solvents include aromatic hydrocarbons and aromatic-aliphatic ethers, preferably aromatic hydrocarbons having 6 to 20 carbon atoms and aromatic-aliphatic ethers. Anisole, mesitylene, xylene, and toluene are particularly preferred solvents.

 Preferably, the thickness of the polymer film produced according to the invention is in the range of 1 nm to 100 microns, preferably at least 10 nm, preferably at least 30 nm, preferably at most 10 microns, preferably at most 1 micron, Is 300 nm or less.

 When the film is prepared by spin coating, the thickness of the spin-coated film is mainly determined by the solids content in the solution and the rotational speed. For example, at 2, 5, 8, and 10 weight percent polymer, at a rotational speed of 2000 rpm, the formulated solution will form a film thickness of 30, 90, 160, and 220 nm, respectively. Preferably, the wet film shrinks by 5% or less after baking and annealing.

 In some embodiments (herein, "gradient" embodiments), the polymers of the present invention exist as "gradient layers" and have a concentration of S1 groups that is not uniform across the thickness of the layer. Since the portion of the gradient layer is sequentially inspected from the portion closest to the anode to the portion closest to the light-emitting layer, the concentration of the S1 period may be monotonically changed or not changed. For example, the concentration of S1 group may be monotone increasing, monotonic decreasing, minimum, maximum, or some combination thereof. The concentration of S 1 can be evaluated by any measurement, including for example the number of S 1 groups per unit volume or the number of S 1 groups per unit mass of polymer.

 In the gradient layer, it is preferable that the concentration of the S1 group is higher in the portion of the gradient layer closest to the anode than in the portion of the gradient layer closest to the light emitting layer. The concentration of S 1 may vary gradually or abruptly or in some other way. Preferably, the portion of the gradient layer is sequentially inspected from the portion closest to the anode to the portion closest to the light emitting layer, so that the concentration of the S1 group in each portion is equal to or less than the concentration of the S1 group in the previous portion. The gradient layer may be constituted by a multi-step process, or the gradient layer may be constituted in some other way to generate a gradient of the volume concentration of the S 1 group. Preferably, the ratio of the concentration of the S1 group in the portion of the gradient layer closest to the anode to the concentration of the S1 group in the portion of the gradient layer closest to the light emitting layer is higher than 1: 1; Or 1.1: 1 or more; Or 1.5: 1 or more; Or 2: 1 or more; Or 5: 1 or more.

 In embodiments where both Si and Si are present in the gradient layer, it is useful to characterize the molar ratio of Si to Si. In the portion of the gradient layer closest to the anode, the molar ratio of S2 to Si is defined herein as MRA: 1. Preferably, the MRA is from 1 to 9. In the portion of the gradient layer closest to the light emitting layer, the molar ratio of S2 group to S1 group is defined as MRE: 1. Preferably, the MRE is from 9 to 999. Preferably, the MRA is less than the MRE. Preferably the ratio of MRA to MRE is less than 1: 1; More preferably 0.9: 1 or less; More preferably 0.67: 1 or less; More preferably not more than 0.5: 1; More preferably 0.2: 1 or less.

 Preferably, the layer of the QLED containing the polymer of the present invention is resistant to dissolution by solvent (solvent resistance is sometimes referred to as "solvent orthogonality"). Solvent resistance is useful since subsequent layers can be applied to a layer containing the composition of the present invention after the QLED layer containing the composition of the present invention is prepared. In most cases, the subsequent layer will be applied by a solution process. In a subsequent solubilization process it is preferred that the solvent does not dissolve or significantly degrade the layer containing the composition of the present invention. Solvent resistance was evaluated using the "strip test" described in the Examples below.

 When the composition of the present invention is present in a HIL, it is preferred that the HIL layer is formed by a solution process. The subsequent layer may be applied to the HIL; The subsequent layer is typically HTL. The HTL can be applied, for example, by a vaporization process (commonly used when the HTL is a small molecule and not containing a polymer) or by a solubilization process (generally used when the HTL contains one or more polymers) have. When the HTL is applied by the solution process, the HIL is preferably resistant to the solvent used in the solution process for applying the HTL.

 When the composition of the present invention is present in the HTL, it is preferred that the HTL layer is formed by a solution process. Subsequent layers can be applied to the HTL; The subsequent layer is typically a light emitting layer. If the subsequent layer is applied by a solution process, it is preferred that the HTL be resistant to dissolution in the solvent used in the solution process for applying the subsequent layer.

 When the composition of the present invention is present in HITL, the HITL is considered to be in contact with the optional additional hole injection layer on one side, the light emitting layer on the anode and the other side, or an optional electron blocking layer. If HITL is used, any additional HIL or HTL is inevitably not present in the QLED.

 When the layer containing the polymer of the present invention is applied to a substrate using a solution process, the solution process is preferably carried out as follows. Preferably, a solution containing the polymer of the present invention dissolved in a solvent is formed. Preferably, a layer of the solution is then applied to the substrate (preferably the substrate is the anode or previous layer of the QLED) and the solvent evaporates or becomes vaporizable to form a film. Then, the thin film is heated to 170 DEG C or higher, more preferably 180 DEG C or higher; It is more preferable to heat to a temperature of 200 DEG C or higher.

Preferably, the exposure time to the high temperature atmosphere is at least 2 minutes; More preferably 5 minutes or more. Preferably the atmosphere is inert; More preferably, the atmosphere contains oxygen gas of 1% by weight or less; More preferably, the atmosphere contains nitrogen of 99 wt% or more.

Example

Preparation Example 1: Synthesis of Monomer S101 Outline:

Preparation Example 2: Preparation of 3- (3- (4 - ([1,1'-biphenyl] -4-yl (9,9- 9-yl) benzaldehyde: < RTI ID = 0.0 >

 To a round bottom flask was added carbazole (9.10 g, 15.1 mmol, 1.0 eq.), 3-bromobenzaldehyde (2.11 mL, 18.1 mmol, 1.2 eq.), CuI (0.575 g, 3.02 mmol, 0.2 eq.), Potassium carbonate , 45.3 mmol, 3.0 eq.) And 18-crown-6 (399 mg, 10 mol%). The flask was flushed with nitrogen and connected to a reflux condenser. 55 mL of dry, deaerated 1,2-dichlorobenzene was added and the mixture was heated to 180 < 0 > C overnight. Only partial conversion was observed after 14 hours. Additional 2.1 mL of 3-bromobenzaldehyde was added and heating was continued for a further 24 hours.

The solution was cooled and filtered to remove solids. The filtrate was concentrated and adsorbed onto silica and purified by chromatography (0 to 60% dichloromethane in hexanes) to give the product as a light yellow solid (8.15 g, 74%). ^{1 H NMR (500 MHz, CDCl} 3) δ 10.13 (s, 1H), 8.39 - 8.32 (m, 1H), 8.20 (dd, J = 7.8, 1.0 Hz, 1H), 8.13 (t, J = 1.9 Hz, 1H), 7.99 (d, J = 7.5 Hz, 1H), 7.91 - 7.86 (m, 1H), 7.80 (t, J = 7.7 Hz, 1H), 7.70 - 7.58 (m, 7H), 7.56 - 7.50 (m , 2H), 7.47-7.37 (m, 6H), 7.36-7.22 (m, 9H), 7.14 (ddd, J = 8.2,2.1, 0.7 Hz, 1H), 1.46 (s, 6H). ¹³ C NMR (126 MHz, CDCl ₃ ) δ 191.24, 155.15, 153.57, 147.22, 146.99, 146.60, 140.93, 140.60, 139.75, 138.93, 138.84, 138.17, 136.07, 135.13, 134.42, 133.53, 132.74, 130.75, 128.75, 128.49 , 127.97, 127.79, 127.58, 126.97, 126.82, 126.64, 126.51, 126.36, 125.36, 124.47, 124.20, 123.94, 123.77, 123.60, 122.47, 120.68, 120.60, 120.54, 119.45, 118.88, 118.48, 109.71, 109.58, 46.88, 27.12 .

 Preparation Example 3: Preparation of N - ([1,1'-biphenyl] -4-yl) -9,9-dimethyl-N- (4- (9- (3-vinylphenyl) Yl) phenyl) -9H-fluorene-2-amine (S101).

 Under a nitrogen blanket, a round bottom flask was charged with methyltriphenylphosphonium bromide (14.14 g, 39.58 mmol, 2.00 eq.) And 80 mL dry THF. Potassium tert-butoxide (5.55 g, 49.48 mmol, 2.50 eq.) Was added in one portion and the mixture was stirred for 15 minutes. The aldehyde of Preparation 2 (13.99 g, 19.79 mmol, 1.00 eq) was added to 8 mL dry THF. The slurry was stirred overnight at room temperature. The solution was diluted with dichloromethane and filtered through a silica plug. The pad was rinsed with several fractions of dichloromethane.

The filtrate was adsorbed onto silica and purified twice by chromatography (10-30% dichloromethane in hexanes) to give the product as a white solid (9.66 g, 67%). The purity was raised to 99.7% by reverse phase chromatography. ^{1 H NMR (400 MHz, CDCl} 3) δ 8.35 (d, J = 1.7 Hz, 1H), 8.18 (dt, J = 7.7, 1.0 Hz, 1H), 7.68 - 7.39 (m, 19H), 7.34 - 7.23 ( m, 9H), 7.14 (dd , J = 8.1, 2.1 Hz, 1H), 6.79 (dd, J = 17.6, 10.9 Hz, 1H), 5.82 (d, J = 17.6 Hz, 1H), 5.34 (d, J = 10.8 Hz, 1H), 1.45 (s, 6H). ¹³ C NMR (101 MHz, CDCl ₃ ) δ 155.13, 153.57, 147.26, 147.03, 146.44, 141.29, 140.61, 140.13, 139.55, 138.95, 137.99, 136.36, 135.98, 135.06, 134.36, 132.96, 130.03, 128.74, 127.97, 126.96, 126.79, 126.63, 126.49, 126.31, 126.11, 125.34, 125.16, 124.67, 124.54, 123.90, 123.55, 123.49, 122.46, 120.67, 120.36, 120.06, 119.44, 118.83, 118.33, 115.27, 110.01, 109.90, 46.87, 27.12 .

 Production Example 4: Protocol for Radical Polymerization.

 In the glove box, the S101 monomer (1.00 eq.) Was dissolved in anisole (electronic grade, 0.25 M). The mixture was heated to 70 < 0 > C and an AIBN solution (0.20 M in toluene, 5 mol%) was injected. The mixture was stirred for at least 24 hours (monomers were completely consumed) (2.5 mol% fraction of AIBN solution was added and completely converted). The polymer was precipitated with methanol (10 times the volume of anisole) and separated by filtration. The filtered solid was rinsed with a further portion of methanol. The filtered solid was redissolved in anisole and the precipitation / filtration procedure was repeated two more times. The separated solids were placed in a vacuum oven at 50 < 0 > C overnight to remove residual solvent.

 Production Example 5: Measurement of molecular weight of polymer

The gel permeation chromatography (GPC) study was carried out as follows. 2 mg of HTL polymer was dissolved in 1 mL of THF. The solution was filtered through a 0.2 μm polytetrafluoroethylene (PTFE) syringe filter, and 50 μl of the filtrate was injected into the GPC system. The following analytical conditions were used: Pump: Waters ™ e2695 separation module at 1.0 mL / min nominal flow rate; Eluent: Fisher Scientific HPLC grade THF (stabilized); Injector: Waters e2695 separation module; Column: Two 5 占 퐉 mixed-C columns of Polymer Laboratories Inc. maintained at 40 占 폚; Detector: Shodex RI-201 Differential Refractive Index (DRI) detector; Calibration: fit to a polynomial curve of 17 polystyrene standards from Polymer Laboratories Inc. in the range of 3742 kg / mol to 0.58 kg / mol.

 Example 6: Oxidation of polymer

In the glove box, the HTL polymer as prepared in Preparative Example 4 was dissolved in anisole (14 mL / g polymer) and the Inorg. Chem. 2012, 51, oxidant (Ag (I) tetra (pentafluorophenyl)) as described in 2737-2746 borate was added in a single portion. After stirring at ambient temperature (about 23 ° C) for 24 hours, the solution was filtered through a 0.2 μm syringe filter. The material may be used in solution, or the polymer may be precipitated by the addition of excess methanol. Various polymers were prepared as follows using various amounts of oxidizing agents:

Polymer assignment Equivalent of oxidant per equivalent of monomer

p (S101) -00 The comparative polymer prepared in Preparation Example 4

P (S101) -02 0.02

P (S101) -05 0.05

P (S101) -10 0.10

An alternative method that can be used to oxidize the polymer is as follows. In a glove box, a round bottom flask can be filled with HTL polymer and dichloromethane (50 mL of polymer per gram). The same amount of acetonitrile can be slowly added to prevent the precipitation of the substrate. NOBF ₄ (0.0642 M in acetonitrile, 0.1 eq.) Can be added in a red-eye fashion to turn the solution into a deep green color. The mixture can be opened by stirring in a surrounding glove box atmosphere for 30 minutes. The solvent can be removed with a vacuum pump.

 Production Example 7: Experimental procedure

Preparation of HTL solution preparation: HTL polymer solid powder was directly dissolved in anisole to prepare a 2 wt% stock solution. A solution for a complete dissolution at 80 ℃ for 5-10 minutes and the mixture was stirred in N _2. The resulting formulation solution was filtered through a 0.2 [mu] m PTFE syringe filter before deposition on a Si wafer.

Preparation of polymer films: Si wafers were pre-treated with UV-ozone for 2 to 4 minutes before use. A few drops of the filtered solution of the above were deposited on the pretreated Si wafer. And then spin-coated at 500 rpm for 5 seconds and then at 2000 rpm for 30 seconds to obtain a thin film. The resulting film was then transferred to an N ₂ purge box. The "wet" film was pre-blotted at 100 占 폚 for 1 minute to remove most of the residual anisole. The film was then thermally crosslinked (described in detail below) at a temperature of 160 ° C to 220 ° C for a period of 10 to 30 minutes.

Strip tests on thermally annealed polymer films were performed as follows. The "initial" thickness of the thermally crosslinked HTL film was measured using an M-2000D ellipsometer (JA Woollam Co., Inc.). A few drops of o-xylene or anisole were then added to the film to form pellets. After 90 seconds, the solvent was spun at 3500 rpm for 30 seconds. The "strip" thickness of the film was measured immediately using an ellipsometer. The film was then transferred to an N ₂ purge box and post baked at 100 ° C for 1 minute to remove the swollen solvent from the film. The "final" thickness was measured using an ellipsometer. Film thickness was determined using the Cauchy relationship and averaged over 3 x 3 = 9 points in the 1 cm x 1 cm area. For a complete solvent resistant film, the total film loss ("final" - "initial") after strip testing should be <1 nm, preferably <0.5 nm.

 Example 8: Strip test using o-xylene

The film was prepared and stripped as described above. The films were annealed at 150 캜 and 180 캜 for 20 minutes or 205 캜 and 220 캜 for 10 minutes. The results are as follows.

Annealing at temperatures higher than 150 ° C improves the resistance of the polymer to stripping by o-xylene. Polymer p (S101) -10 of the present invention is resistant to stripping by o-xylene when annealed above 180 ° C.

 Production Example 9: Synthesis of S102 and S103

 Using a method similar to Preparation Examples 1 to 4, the following monomers were synthesized:

 According to the procedure of Preparation Example 4, homopolymers p (S102) and p (S103) were formed. According to the procedure of Preparation 6, 0.10 equivalent of oxidizing agent was used to form a partially oxidized polymer having aminium radical cations p (S102) -10 and p (S103) -10. The oxidant was (Ag (I) tetra (pentafluorophenyl)) borate.

 Example 10: Calculation of orbital energy

The orbital energy was calculated as follows. The basis state (S ₀ ) composition of the molecules was calculated using density function theory (DFT) with hybrid function (B3LYP) and 6-31 g * base set. Although calculations were performed using a limited approach to these closed shell systems (i.e., neutral molecules), calculations were performed using a non-limiting approach for radical cations (open shell systems containing conjugated electrons). The energy of the HOMO (the highest occupied molecular orbital), SUMO (the sole unoccupied molecular orbital for the radical cation) and the LUMO (the next unoccupied molecular orbital for the radical cation) were obtained from the ground state geometry of the neutral and radical cations. A vibration analysis of this geometry was performed and it was helpful to identify the minimum value on the potential energy surface (PES) because there is no virtual frequency. All calculations are done using Frisch, MJT, GW; Schlegel, HB; Scuseria, GE; Robb, MA; Cheeseman, JR; Montgomery, Jr., JA; Vreven, T .; Kudin, KN; Burant, JC; Millam, JM; Iyengar, SS; Tomasi, J .; Barone, V .; Mennucci, B .; Cossi, M .; Scalmani, G .; Rega, N .; Petersson, GA; Nakatsuji, H .; Hada, M .; Ehara, M .; Toyota, K .; Fukuda, R .; Hasegawa, J .; Ishida, M .; Nakajima, T .; Honda, Y .; Kitao, O .; Nakai, H .; Klene, M .; Li, X .; Knox, JE; Hratchian, HP; Cross, JB; Bakken, V .; Adamo, C .; Jaramillo, J .; Gomperts, R .; Stratmann, RE; Yazyev, O .; Austin, AJ; Cammi, R .; Pomelli, C .; Ochterski, JW; Ayala, PY; Morokuma, K .; Voth, GA; Salvador, P .; Dannenberg, JJ; Zakrzewski, VG; Dapprich, S .; Daniels, AD; Strain, MC; Farkas, O .; Malick, DK; Rabuck, AD; Raghavachari, K .; Foresman, JB; Ortiz, JV; Cui, Q .; Baboul, AG; Clifford, S .; Cioslowski, J .; Stefanov, BB; Liu, G .; Liashenko, A .; Piskorz, P .; Komaromi, I .; Martin, RL; Fox, DJ; Keith, T .; Al-Laham, MA; Peng, CY; Nanayakkara, A .; Challacombe, M .; Gill, PMW; Johnson, B .; Chen, W .; Wong, MW; Gonzalez, C .; And Pople, J. A; A.02 ed .; Gaussian Inc .: Wallingford CT, 2009.

In both S101 and S103, the SUMO orbital energy of the radical cation is similar to the HOMO orbital energy of the neutral molecule. This result is considered to mean that the radical cation acts as a p-dopant when the radical cation is mixed with the neutral molecule so that the mixture can function as HIL and / or HTL. The orbital energies shown in the above table can be used to design device structures, including the use of specific materials for HIL, HTL, and EBL.

QLED device manufacturing

The QLED device is configured as follows. A glass substrate (20 mm x 15 mm) having pixelated tin-doped indium oxide (ITO) electrodes (Ossila Inc.) was used. ITO was treated with oxygen plasma. The hole-injecting layer (HIL) was Plexcore ™ OC RG-1200 (poly (thiophene-3- [2- (2-methoxyethoxy) ethoxy] -2,5-diyl available from Sigma-Aldrich A solution of 20 μL of solution was dispensed onto the rotating substrate by filtering the HIL solution through a 0.45 micron polyvinylidene fluoride (PVDF) syringe filter and by dynamic spin coating onto the layer. A portion of the deposited film covering the electrode portion was removed with toluene using a foam swab. The device was then annealed at 150 DEG C for 30 minutes on a hot plate in an inert atmosphere .

To form a hole transport layer (HTL), each HTL polymer was individually dissolved in an electronically graded anisole (2% w / w) at elevated temperature (<100 ° C) to ensure complete dissolution and a 0.2 μm polytetra And passed through a fluoroethylene (PTFE) filter. The material was deposited on the layer by dynamic spin coating so that 20 μL of solution was dispensed onto the rotating substrate. To achieve a film thickness of about 40 nm, the rotational speed (about 2000 RPM) was adjusted. A portion of the deposited film covering the electrode portion was removed with toluene using a foam swab. The device was then annealed on a hot plate in an inert atmosphere at 205 DEG C for 10 minutes. (4, 40- (N- (4-sec-butylphenyl)) diphenylamine)] (TFB) and 2, The well-studied literature on HTL consisting of a 50:50 mixture of 3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ) was used as a reference.

The luminescent material was selected from the following list. Each material was deposited on the layer by dynamic spin coating to allow 20 μL of solution to be dispensed onto the rotating substrate. To obtain a film thickness of about 5-15 nm, the rotational speed (about 2000-4000 RPM) was adjusted for each material. A portion of the deposited film covering the electrode portion was removed with toluene using a foam swab. The device was then annealed on a hot plate in an inert atmosphere at 180 &lt; 0 &gt; C for 10 minutes.

The luminescent layer materials used are as follows:

1) CdSe / ZnS (520 nm emission);

2) InP / ZnS (620 nm emission); And

3) CdS / CdSe / ZnSe DHNR (600 nm emission).

CdSe / ZnS and InP / ZnS were purchased from Aldrich as catalog numbers 748021 and 776777, respectively. The quantum dots were dispersed in toluene at a concentration of ~ 20 mg / ml, which was used as is.

DHNR  Was synthesized according to the following procedure.

(90%), industrial trioctylphosphine oxide (90%), industrial trioctylphosphine (TOP) (90%), industrial oleic acid (90%), industrial octadecene (90%), CdO (99.5% ), S powder (99.998%), and Se powder (99.99%) were obtained from Sigma Aldrich. N-octadecylphosphonic acid (ODPA) was obtained from PCI Synthesis. ACS grade chloroform and methanol were obtained from Fischer Scientific. All chemicals were used as received.

Synthesis of CdS nanorods: CdS nanorods were prepared in a manner similar to the established method 14 above. The reaction was carried out in a standard Schlenk line under N2 atmosphere. First, 2.0 g (5.2 mmol) of trioctylphosphine oxide, 0.67 g (2.0 mmol) of ODPA and 0.13 g (2.0 mmol) of CdO in a 50-ml 3-necked round- Deg.] C for 30 minutes and then heated to 350 [deg.] C with stirring. As the Cd-ODPA complex was formed at 350 ° C, the brown solution in the flask was typically optically clear and colorless after 1 hour. The solution was then cooled and degassed at 150 캜 for 10 minutes to remove by-products of complexes containing O ₂ and H ₂ O. After stripping, the solution was re-heated to 350 ℃ under N ₂ atmosphere. S precursor containing 16 mg (0.5 mmol) of S dissolved in 1.5 ml of TOP was rapidly injected into the flask with a syringe. As a result, the reaction mixture was quenched to 330 캜 so that the CdS growth was carried out. After 15 minutes, the growth of the CdS nanorods was terminated by cooling to 250 &lt; 0 &gt; C and CdSe growth on the CdS nanorods was performed. Aliquots of CdS nanorods were taken and precipitated with methanol and butanol for characterization and washed. As described below, the Se precursor was slowly added to the same reaction flask maintained under N ₂ atmosphere to form a CdS / CdSe heterostructure.

Synthesis of CdS / CdSe nanorod heterostructures: One-port synthesis of rod-rod-rod nanorod heterostructures was performed in a similar manner to established methods. After formation of the CdS nanorods, a Se precursor containing 20 mg (0.25 mmol) of Se dissolved in 1.0 ml of TOP was slowly injected at 250 ° C through a syringe pump at a rate of 4 ml h ^-1 (total injection time ~ 15 minutes). The reaction mixture was then stirred for an additional 5 minutes at &lt; RTI ID = 0.0 &gt; 250 C &lt; / RTI &gt; An aliquot of the CdS / CdSe nanorodic heterostructure was taken and precipitated with methanol and butanol for analysis and washed. The final reaction mixture was dissolved in chloroform and centrifuged at 2,000 RPM. The precipitate was redissolved in chloroform for the next step. The solution of the CdS / CdSe nanorodic heterostructure has an optical density of 0.75 (in a cuvette with a light path length of 1 cm) at the CdS band-edge absorption peak when diluted to a factor of 10.

Synthesis of CdS / CdSe / ZnSe DHNRs: CdS / CdSe / ZnSe DHNRs were synthesized by growing ZnSe on the CdS / CdSe nanorod heterostructure. For the Zn precursor, 6 mL of octadecene, 2 mL of oleic acid, and 0.18 g (1.0 mmol) of Zn acetic acid were degassed at 150 &lt; 0 &gt; C for 30 minutes. The mixture was under N ₂ atmosphere, heated to 250 ℃, with the result that after one hour, the Zn oleate was formed. 2 mL of the previously prepared CdS / CdSe storage solution was cooled to 50 ° C and then injected into the Zn oleate solution. The chloroform was evaporated at 70 &lt; 0 &gt; C under vacuum for 30 minutes. ZnSe growth was initiated by slowly injecting a Se precursor containing 39 mg (0.50 mmol) of Se dissolved in 2.0 ml of TOP at 250 DEG C into the reaction mixture. The thickness of ZnSe on the CdS / CdSe nanorod heterostructure was controlled by the amount of Se injected. ZnSe growth was terminated by removing the heating mantle after injecting the desired amount of Se precursor. After washing twice with a mixture of chloroform and methanol (1: 1 by volume), CdS / CdSe / ZnSe DHNR was finally dispersed in toluene (~30 mg ml ^-1 ).

Synthesis of ZnO: ZnO was used as an electron transport layer (ETL). ZnO was synthesized according to published literature procedures. Briefly, a solution of potassium hydroxide (1.48 g) in methanol (65 ml) was added to zinc acetate dihydrate (2.95 g) in a solution of methanol (125 ml) and the reaction mixture was stirred at 60 ° C for 2 hours. The mixture was then cooled to room temperature and the precipitate was washed twice with methanol. The precipitate was suspended in 1-butanol to form the final ZnO solution. ZnO was deposited on the layer by dynamic spin coating and 20 μL of the solution was dispensed onto the rotating substrate. To obtain a film thickness of about 30 nm, a rotational speed of about 2000 RPM was adjusted. A portion of the deposited film covering the electrode portion was removed with butanol using a foam swab. The device was then annealed on a hot plate in an inert atmosphere at 120 &lt; 0 &gt; C for 10 minutes.

A 100 nm layer of aluminum was deposited from the graphite crucible through a cathode shadow mask under high vacuum by thermal evaporation.

The QLED device was tested as follows. Current-voltage-optical (JVL) data was collected for the non-encapsulated devices in the N ₂ glove box using a custom test board from Ossila Inc. The board has two components: 1) X100 Xtralien ™ precision test source; and 2) smart PV and OLED boards; These components were combined and used to test the QLED device in increments of 0.1V over a voltage range of -2V to 7V while measuring current and light output. Light output was measured using an eye response photodiode that included an optical filter (Centronic E-Series) that mimics eye sensitivity of nominal response. The device was placed in a test chamber on the board and covered with a photodiode assembly . Electrical contact was made to the ITO electrodes by a series of spring-actuated gold probes in the smart board assembly. A photodiode was placed on the ITO substrate at a distance of 3 mm. From JVL data, 1000 cd / m voltage required to reach a luminance of ^2, 1000 cd / m ² of QLED current efficiency (in cd / A), and the drive voltage required to reach a current of 10 mA / cm ² in QLED Have been determined. Geometric factors were applied to the measured photodiode current to determine the distance between the photodiode and the substrate (3 mm) and the relative position from each pixel on the substrate.

 Results and Analysis

The HTL polymers listed below were prepared with quantum dot light emitting diodes of the Examples. The diodes of the examples were performed in all tests including quantum dots composed of CdSe / ZnS, InP / ZnS, and DHNR. The devices of the Examples were shown to operate to emit quantum dots in the 520 to 600 and 620 nm ranges, as listed in the table below. The devices of the Examples were shown to work with both spherical and bar size quantum dots.

Claims (12)

The present invention relates to a process for the preparation of a compound of the formula (I), a compound of the formula II-VI, a compound of a group II-V, a compound of a group III-VI, a compound of a group III-V, a compound IV- A light-emitting layer of at least one semiconductor nanoparticle made of a semiconductor material selected from the group consisting of Group IV-V compounds, or any combination thereof, and ii) at least one triarylammonium radical cation having a structure (S1) A quantum dot light emitting diode comprising a hole injection or polymer for a hole transporting layer,

Each ^{R 11, R 12, R 13} , R 14, R 15, R 21, R 22, R 23, R 24, R 25, R 31, R 32, R 33, R 34, and R ³⁵ is hydrogen, Wherein R ¹¹ , R ¹² , R ¹³ , R ¹⁴ , R ¹⁵ , R ²¹ , R ²² , and R ²⁴ are independently selected from the group consisting of hydrogen, deuterium, halogen, amine groups, hydroxyl groups, sulfonate groups, nitro groups, Two or more of R ²³ , R ²⁴ , R ²⁵ , R ³¹ , R ³² , R ³³ , R ³⁴ , and R ³⁵ are optionally linked together to form a ring structure;
^{R 11, R 12, R 13} , R 14, R 15, R 21, R 22, R 23, R 24, R 25, R 31, R 32, R 33, R 34, and R ³⁵ at least one of the said Covalently bonded to the polymer,
A ^- is an anion, a quantum dot light-emitting diode. The device of claim 1, wherein the diode comprises a dual function layer that functions as a hole injection layer and a hole transport layer, the diode does not include any additional hole injection layer or hole transport layer, RTI ID = 0.0 &gt; S1). &Lt; / RTI &gt; 3. The diode of claim 2, wherein the diode further comprises at least one electron blocking layer. The diode of claim 1, wherein the polymer is a vinyl polymer or a conjugated polymer. The diode of claim 1, wherein the polymer further comprises at least one triarylamine structure (S2).

Each ^{R 11, R 12, R 13} , R 14, R 15, R 21, R 22, R 23, R 24, R 25, R 31, R 32, R 33, R 34, and R ³⁵ is structure ( RTI ID = 0.0 &gt; S1). &Lt; / RTI &gt; 6. The diode of claim 5, wherein the molar ratio of structure S2 to structure S1 is 999: 1 to 0.001: 1. 6. The method of claim 5, wherein the diode comprises a gradient layer positioned between the anode layer and the light emitting layer and including S1 and S2 groups, wherein the molar ratio of S2 to Si groups is not uniform across the gradient layer , A diode. 8. The method of claim 7, wherein the molar ratio of S2 to S1 in the portion of the gradient layer closest to the anode layer is defined as MRA: 1, and the molar ratio of S2 to S1 in the portion of the gradient layer closest to the light- MRE: 1, wherein the MRA is less than the MRE. 9. The diode of claim 8, wherein the ratio of MRA to MRE is 0.9: 1 or less. 2. The diode of claim 1, wherein the composition further comprises one or more polymers that do not have structure (S1). The diode of claim 1, wherein the polymer has a number average molecular weight of 2,500 to 300,000 Da. The composition of claim 1, wherein A ^- is selected from the group consisting of BF ₄ ^- , PF ₆ ^- , SbF ₆ ^- , AsF ₆ ^- , ClO ₄ ^- , anions of structure SA, anions of structure MA, , The structure SA

(SA)
Wherein each R ⁶¹ group, each R ⁶² group, each R ⁶³ group, and each R ⁶⁴¹ group is independently selected from the group consisting of deuterium, Halogen, alkyl, and halogen-substituted alkyl, and any two groups selected from the R ⁶¹ group, the R ⁶² group, the R ⁶³ group, and the R ⁶⁴¹ group may be optionally bonded together Ring structure, and the structure MA is

(MA)
Wherein M is B, Al, or Ga, and each of R ⁶² , R ⁶³ , R ⁶⁴ , and R ⁶⁵ is independently alkyl, aryl, fluoroaryl, or fluoroalkyl.